A class of pharmaceutical agents known as .beta.-adrenergic blocking agents, are available which affect cardiac, vascular and pulmonary functions and are mild antihypertensives. .beta.-adrenergic blocking agents, their chemical structure and activity, are disclosed in Clinical Pharmacology and Therapeutics, 10, 292-306 (1969). Various .beta.-adrenergic blocking agents are also described in the following patents: U.S. Pat. No. 3,048,387; U.S. Pat. No. 3,337,628; U.S. Pat. No. 3,655,663; U.S. Pat. No. 3,794,650; U.S. Pat. No. 3,832,470; U.S. Pat. No. 3,836,666; U.S. Pat. No. 3,850,945; U.S. Pat. No. 3,850,946; U.S. Pat. No. 3,850,947; U.S. Pat. No. 3,852,291; U.S. Pat. No. 4,134,983; U.S. Pat. No. 4,199,580; U.S. Pat. No. 4,115,575; U.S. Pat. No. 4,195,090; British Pat. No. 1,194,548; and South African Pat. No. 74/1070.
Now, with the present invention there are provided novel cardioselective .beta.-blocking agents which have the capability of reducing heart rate, without counteracting vasodepression or suppressing bronchodilation; processes for their synthesis, pharmaceutical formulations comprising one or more of the novel compounds; and methods of treatment with the novel compounds or pharmaceutical compositions thereof wherein an antihypertensive, cardioprotective, antiarrhythmic or antianginal agent is indicated.